obspy @MacPorts updated to 0.8.4

Hi ObsPy users,

this short might be useful to some of the Mac users and just to let them know that the py-obspy MacPort (www.macports.org) update to 0.8.4 was finally committed tonight and is now available via MacPorts.

Especially, for users which already use MacPorts to manage their packages this should be a very convenient method to install ObsPy on various Mac OS X versions along with other python packages. Not yet MacPorts users might give it a try. It is really convenient :wink:

I also propose that this option is mentioned on https://github.com/obspy/obspy/wiki/Installation-on-Mac.

Limitations with Python 2.6:

- The port should install and run smoothly with Python 2.7 (py27-obspy).

- With Python 2.6 there seem be some issues, which I assume are not directly related to ObsPy or the port itself. If gcc >=4.5 (variant +gcc45 .. +gcc47) is used to compile scipy (py26-scipy) and py26-obspy, the port would install without problem, but will not be completely functional.

If you need to install it with Python 2.6, please use the following procedure:
- install scipy w/ the +gcc44 variant: `sudo port -v install py26-scipy +gcc44`
(Note: py26-scipy +gcc47, the default is currently not functional anyway)
- install obspy w/ the +gcc44 variant: `sudo port -v install py26-obspy +gcc44`

The gcc43 would work as well.

In case you encounter any problem do not hesitate to send me a note or to fill a ticket against the port.